优化

app/src/main/java/io/legado/app/ui/book/cache/CacheViewModel.kt

@@ -122,11 +122,9 @@ class CacheViewModel(application: Application) : BaseViewModel(application) {
             exportMsg[book.bookUrl] = context.getString(R.string.export_success)
             upAdapterLiveData.postValue(book.bookUrl)
         }.onFinally {
-            mutex.withLock {
             exportNumber--
         }
     }
-    }
 
     @Suppress("BlockingMethodInNonBlockingContext")
     private suspend fun export(doc: DocumentFile, book: Book) {
@@ -287,11 +285,9 @@ class CacheViewModel(application: Application) : BaseViewModel(application) {
             exportMsg[book.bookUrl] = context.getString(R.string.export_success)
             upAdapterLiveData.postValue(book.bookUrl)
         }.onFinally {
-            mutex.withLock {
             exportNumber--
         }
     }
-    }
 
     @Suppress("BlockingMethodInNonBlockingContext")
     private suspend fun exportEpub(doc: DocumentFile, book: Book) {